Positive bridge-action for platen printing-presses



(No Model.)

J. THOMSON. v POSITIVE BRIDGE ACTION FOR PLATEN PRINTING PRBSSBS.-. No. 367.867.

Patented Aug. 9, 1887.

N. PETERS Fhokodilhagnpher, washin mn, D. c.

UNITED STATES PAT NT OFFI E;

JOHN THOMSON, OF BROOKLYN, NEW YORK, ASSIGNOR To THE COLTS PATENT FIREARMS MANUFACTURING OMPANY, OF HARTFORD,

CONNECTICUT.

POSITIVE BRlDGE-ACTION FOR PLATEN PRlNTlNG-PRES SES.

SPECIFICATION forming part of Letters Patent No. 367,867, dated August 9, 1887.

Applicationfiled June 8, 1SE6. Serial No. 204,526. (No niodeL) To all whom it may concern:

Be it known that 1, JOHN THOMSON, a citizen of the United States, and a resident of the city of Brooklyn, county of Kings, and State of New York, have invented certain new and useful Improvements in Positive Bridge-Actions for Vibrating Platen-Presses, of which the following is a specification.

This invention consists in a device for controlling the plateiraction of jaw-presses of that class in which the platen is caused to slide directly to'or from the bed prior and subsequent to'the instant of impression, but during all other portions of its action to roll on a table .or seat.

I11 Figure 1 is represented a vertical section and elevation of such a platen-action, showing the application of my invention. Fig. 2 is a detached top plan view of the same.

V vnoon practice.

There is here presented the usual arrangement of the parts to which my device is applicable, 3 representing the bed, 4 the framing, 5 the rockerseat, 6 the platen, 7 the rocking block or bridge, 8 therocker, 9 the ear of said rocking block, and 10 10 the lugs forming a part of the ear, and which engage the rocker-seat during the direct sliding action. Motion is imparted tothe block by a connecting-rod, 11, journaled on the blockshaft '12, the extension of said connecting-rod being connected with the power membersuch as a crank or toggle-arranged to impart a reciprocating motion to the rod, all as in eom- The usual mode ofcontrolling such actions ,is to connect the rocking block to the frame-by means of a link and spring,

in fact simulating an extensible links The spring or springs must be of such character as to permit the direct sliding motion against their tension, in which the platen assnmesthe position of dotted outline 13; but at all other times of the action, or until the platen assumes position 14,"the springs must be sufiiciently stiff to cause the rocking block to keep its proper position on the rocker-seat. The duty required of the springs is exceedingly severe in consequence of the fact that the point at which the link is connected to the rocking block, as 15, if free to develop the path due to the rocker having its center at 16, would describe the are of a Cycloidal curve, as 17; but as the vibrating link describes the arc of a circle, as 18, the rocking block is thus caused to differentially roll and grind, the extent of, the grind being equal to the difference in the curves.

The present invention obviates the use of springs by substituting therefor a positive ac tion, the construction and operation of which is as follows: The"heel 19 of the link 20 is arranged to straddle the bearing and sliding block 21, and from the body ofthe link two Segments, 22, are formed to the-arc of a circle, whose center 23 is also the center upon which the link vibrates. Attached to the frame by bolts, as 24,is a bracket, 25, also having two segments, 26, corresponding to those of the link. The lower surfaces, 27, of the bracketsegments and the upper surfaces, 28, of the link-segments are then squared OH to a plane corresponding to the direct motion of therock= ing block. It will now be seen that if the motion of the rocking block be toward the left hand of thedrawings,orthe outmotion, the two pairs of segments will interlock and cause the rocking block to partake of the mot-ion of the link, the heel of the said link during such time being in fact a fixed bearing capable only of vibration; but if the, motion of the block be toward the right hand,or the inmotiOn,t-he plane surfaces 27 28 of the segments will pass upon each other, the sliding block being drawn forward on the stud 29, thus permitting the proper sliding motion ofthe platen prior to and dur ing the impression. The inmotion is particularly registered by the face of the lug 10 impinging and sliding upon the lower surface of the rocker-seat. Upon the reverse motion the lug 10slides back upon theuppcr surface of the rocker-seat, thereby relieving the plane surfacesof the segments of excessive or cramping strain until the sliding block makes Contact with the face of the bracket, when the rocking block is caused to tilt and the segments interlock, as before described. The engagement of the lugs 10 10 and the plane surfaces of the segments are timed to be practically simultaneous.

This device. is compact, durable, and inexpensive, and aside from the advantage of dispensing with springs, it is capable of being applied to presses already in use.

I claim 1. The combination of the sliding and rocking block, a link connected thereto, a bracket having sliding bearings for the link, and interlocking segments upon the link and bracket controlling the movement of the block, substantially as described.

2. The rocking block, link, and bracket, said link and bracket having segments, the form and construction being such as to alternatelypermit the alternating sliding and rocking motion of the rocking block, substantially as described.

3. The combination, with the rocking block and the fixed bracket, having two segments, of the link pivotally connected to the rocking block and to a sliding bearing-block, 21, the said link having two segments adapted to engage the segments of the bracket, whereby the rocking block is caused to rock and slide at the proper intervals, substantially as specified.

4. The combination of the rocker-seat, the sliding and rocking block, lugs on the block engaging the seat, a link connected to the block, a bracket carrying a sliding bearing for the link, and segments upon the bracket and link, substantially as described.

In testimony whereof I have signed my name to this specificationinthepresence of two subscribing witnesses.

JOIIN THOMSON.

Witnesses:

\VILLIAM TIIoMsoN, OLIVER N. PAYNE. 

